Senecio barbetonicus is a succulent shrub that branches from the base and higher up to form a rounded shape. Leaves dropping off old stems leave notable scars or persistent rough bits on the otherwise bare, lower stems. The plant is evergreen and hairless, but the younger stems are green turning brown and woody at maturity.
Flowering stems protrude above the leaves and bear composite yellow flower heads in small flat-topped clusters. Flowers are tubular and sweetly scented. Plant in sun or semi-shade.